Ketosiloxanes



Patented Dec. 15, 1953 :u-Nwe!) PATENT o Fries -Dow Corning jGo 'noi-ation, Midland, v Mich., va corporation of Michigan No Drawing. Application beasiberiiazrssi, Serial No. 281;597

8 Claims.

This invention relates to enemies having a carbonyl group in them'ole'cule. V

"It is an object of this inventiontopreparenew polymeric siloxanes'which have iunctional'groups in the polymer chains.

Conventional :sil'oxanes :which may be rcopoly' merized with those of this invention may be either monoorganosiloxanes such as *phenylsilicic acid, phenylsilsesquioxane, :inethylsilsesquioxane and butylsilicicacid; or :diorganosiloxanes such In this application Me designates the methyl 0 as 'rdimeth-ylsiloxane, .sphenylmethylsiloxane, di-

radical. tolylsiloxane, stearylmethylsiloxane, and naph- -This invention relates to polysiloxanes in thylmethylsiloxan e; or :triorganosiloxanes such which the polymer units are of the formula as ,hexamethyldisiloxane, hexaphenyldisiloxane,

, v and tetraamyldiphenyldisiloxane.

[MezSuCHfl "CO'(OH2)"S1Me2O] m :In order-for theketosiloxanes of-thisrinvention W ere n a Value 'fi usive. to have-anyappreciable effect-onrthecopolymers,

Thefabov'e ipolymers'are'prep re y cl v they should be ;present in amount of at least ketones of the formula [R'MeSKCHzJiliCO moimoliper cent. where'R""is'a'methyl'oriphnyl aid bal i f j IIhe ,=ketosiloxanes of this invention exhibit as above defined, "with sulphuric acid followed .otherstandardbehavioncommonto conventional byhydrolysis of the sulphate with water. The siloxanes For (example, ,they ma.y be depglyreactions involved are cleavage of theft group merized by heating at temperaturesabove 350 f the siliconby h lp ric aci'd to give C. under reduced pressure. rUnder such "condia'silylsulp'hat'e andhiethjane or 'benzene depend tions 'cyclic rpolymers are :obtained. The 'rearing upon whether the R group "is methyl 0 rangement may be-earriednumat lower temperaphenyl, respectively, Thesulphate group is then tures such as 250 C. if acidic catalysts are emremoved from the silicon by hydrolysis whereployed. upon :a :silanol is formed which condenses a The fketosilanes for the formula polysiloxane. w i.

The above described siloxanesnnay be :either 60 [RKMEZSKCHZMhC'O m 9 flammm which are employed as starting materials in this polymers "F 9 w f ja 9 invention are described and claimed "in the apsame) obtamed f lwsmgleketosll' plicants *cohending a inlication Serial Number oxanswlih sulpburlc acld m? thereafter 2615602 ehtitleii "Bis Trioganosilyl substituted dl'Plyzmg rm g copolymers may be Ktonesi filed concurrently'h'erewith. '-In brief, tamed by treating a mixture of 2 or more of the theseketbneis m be?prepared:byCOhdmSmg -es i i i fi W $419, Fi ters of ithe 'io'r mu'l a PRMe2S-iKCH2MCOOEt with lowed'by hydrolysls. rnreaamme-one may diiscs ircpyiamnmfimm magnesium bromide Tol- Pare a 3??? l e g iu e of 01,16 lowed b'y'decaiboxylationiof*theresulting*betaof the above'ketones 1n vvhich n 1s 2 random in r with-acids t Wm 1S resulting P m y W111 than The"materials of this "invention are useful as 1P e hfiym Q m additives for conventional siloxanes. They are In adfiltlon' mf$ -hs- P ..bY also usefulasintermediatesinfthe'preparation of interacting the ketosiloxanes of this invention resinous xmaterials in which crosklmking is with conventlonal s1loxanes of the formula ugfit 'a qtithroifghtlie carbonyl group.

iasio reliev ng 'feiramfiles are illustrative only T ana are notjjtobfe construed "as limiting the inp I v vention which is"proper1y'st forthin'the'appendwhereiR'isiany mcnovalent hydroearbonradical ed claims free of aliphatic unsaturated, and has=ayalue Examgjl "1 from 1 to 3, :inclusive. These copolymers are 3 obtained by interacting one or more of the above grams of 232,8,8'tetmmethylzisdlsllaf5' ketosfloxanes with one .more bf :the nonaneone, Mes"S1(CHz) 2]2CO-, was treated with conventional siloxanes. This interaction may '50 200 grams f c'qncentmted sulfuric 'acid' The best "be carried out in the presence of catalysts ketone Was added slowly to he d a d the resuch as acids, salts and alkalies. Preferably, the action mixture wa '0 ed "With Water. There catalyst employed is acidic in nature since al- Was a vigorous v u on f as. When the evokaline materials tend to cause undesirable side lution had ceased the mixture was slowly poured reactions of the carbonyl group. onto cracked ice. The resulting organic material was extracted with ether. The combined extracts were dried and the ether removed.

The resulting product was distilled at atmospheric pressure in astream of nitrogen leaving a residue of a highly viscous polymeric material in which the unit formula was The distillate was redistilled at reduced pressure and there was obtained on oily material boiling from 58 C. at 52 mm. to 153 C. at 6 mm. This material was a mixture of polymers in which the repeating unit was [OSiMC-iz (CH2) 2C0 (CH2) 231M821 These mixed polymers reacted with 2,4-dinitrophenylhydrazine to give oily and amorphous products.

Example 2 Employing the method shown in Example 1, 138 grams of 2,2,8,8-tetramethyl-2,8-disila-- nonaneone was added over a period of 2%; hours to 4'75 grams of concentrated sulfuric acid. After hydrolysis and washing 134 grams of a viscous polymeric ketosiloxane remained.

This polymeric ketone was rearranged by heating at 37 to 385 C. under a pressure of 3 to 5 mm. There was obtained 112.5 grams of distillate which consisted of both a solid and a liquid phase. The solid was filtered and recrystallized from 95 per cent ethyl alcohol whereupon 30.1 grams of a white crystalline solid melting point 129 to 130 C. was obtained. This material was found to have molecular weight of 4:25 and to contain 25.7 per cent silicon. This shows that the material was a cyclic dimer of the formula [1VI62S1(CH2)2CO(CH2)2S1M20]2.

The liquid portion of the distillate amounted to 66 grams and had a refractive index of 1.4575 at 20 C. This material was a mixture of higher cyclics of the polymeric ketone.

Example 3 58.5 grams of the liquid polymer fraction obtained in Example 2 was mixed with 187 grams of hexamethyldisiloxane and 35 ml. of the concentrated sulfuric acid. The mixture was stirred at room temperature for four hours. At the end of this time, 100 ml. of water was added and the mixture was stirred for minutes. The organic layer was washed twice with water and then dried over anhydrous KgCOa. The excess hexamethyldisiloxane was distilled at atmospheric pressure and the residue was then fractionated. The first product obtained boiled at 95 C. at 2 mm. pressure and had a refractive index of 1.4262 at C. This material was the polymer Me Me Me: SiO Si( CH2)2C 0 011m SiOSiMEs Me Me The compound was reacted with 2,4-dinitrophenylhydrazine and there was obtained a solid derivative which, after recrystallization from an alcohol-chloroform mixture melted at 245 to 247 C.

The residue from the distillate was a liquid which was composed of higher copolymers having the formula where :c is greater than 1.

Example 4 When the ketones shown below are treated with concentrated sulfuric acid and the resulting product thereafter hydrolyzed as shown in Example 1, siloxane polymers in which the polymer units are those shown below, are obtained. In each case, the polymers are viscous materials which are mixtures of molecules of varying molecular weight.

Ketone Unit formula of polymer produced Me3Si(CH2)i]]2C0 {MQQSKCHQMCO(CHmSIMeQOL MeaSKCHQmCO MezSi(CHz)4CO(CH:)lsiMezol. C H Me;S1(CHz)5]zCO [Me SKCHmC0(CH2)5SlMe O].

Example 5 When .1 gram mol of a siloxane having the unit formula [MezSi(CH2)3CO(CH2)3SiMe2O] is copolymerized with 0.9 gram mol of phenylmethylsiloxane by the method shown in Example 3, a liquid copolymer composed of 10 mol per cent of the former siloxane units and mol per cent of the latter siloxane units is obtained.

Example 6 in which n has a value from 2 to 5 inclusive.

. A siloxane of claim 1 where n is 2.

. A siloxane of claim 1 where n is 3.

. A siloxane of claim 1 where n is 4.

. A siloxane of claim 1 where n is 5.

5! economic Me Me MeaSiO SI(CHQ)ZC O CHmSiOSiMca Me Me 8. A polysiloxane consisting essentially of --MezSi (CH2) nCO (CH2) 11SiMezO- polymer units where n has a value of 2 to 5 inelusive and up to .999 mol per cent polymer units having the general formula R..SiO T where R is a monovalent hydrocarbon free of aliphatic unsaturation and :c has a value of from 1 to 3 inclusive.

LEO H. SOMMER.

References Cited in the file of this patent Sommer et al.: Journ. Amer. Chem. Soc, vol. 73, 1951, page 882. 

1. A POLYSILOXANE IN WHICH ALL OF THE POLYMER UNITS ARE OF THE FORMULA 